These are the service line and emergency line. They attach to both the truck the semi trailer. The service air line is blue and will carry air that is controlled by the foot brake in the truck or the trailer hand valve.The service line is connected to a relay valve on the semi trailer and will apply pressure on the semi trailer brakes.he hand valve is never used in stopping, as it will cause the trailer to skid and possibly jackknife. The foot brake of the truck will also operate the brakes and prevent such events from occurring. The trailer air supply control is red 8-sided knob, which controls the tractor protection valve.
Sponsored Topics. Cannon Falls is a city in Goodhue County, Minnesota, United States. The population was 4,083 at the 2010 census. Located along U.S. Route 52 to the southeast of the Twin Cities, Cannon Falls may be best known as the home of Pachyderm Studio, where many famous musicians have recorded their music.
Kit # 17985 â John P.Cannon born February 27, 1778 in Ireland and died April 2, 1833 in Parke County, Indiana. He married Margaret Hayes who was born February 2, 1784 in Lincoln County, Kentucky and died March 29, 1857 in Parke County, Indiana.it # 17984 â Curtis W.Cannon born about 1750 in Delaware or Maryland and died about 1835 in Ohio. He married Rebecka LNU who was born about 1773 in Maryland and died in Adams County, Ohio. GROUP 05 This group is part of the Irish Type III Cluster. Kit # N13807 â Brian Cannon born 1840 in County Donegal, Ireland.